1. Field of The Invention
The present invention relates to servicing various components of a magnetic tape player of the cartridge type and more particularly relates to a kit for effecting cleaning, testing and alignment of the player components.
2. Description of The Prior Art
Recently, the use of cartridge-type prerecorded tapes, and particularly those of the 8-track variety, has become extremely widespread. Along with the convenience and pleasure which these cartridges provide, have come problems which are peculiar to the construction of the playback units.
The playback units of the cartridge-type include playback heads and related structures which are normally mounted in an enclosed location, since the cartridges are positioned for playing by being inserted in a slot-like aperture. It has been found that the playback head, the drive capstan, the sensing poles utilized for switching tracks in an 8-track tape and other related components of the playback unit, which contact the moving tape or which are immediately adjacent to the moving tape, tend to accumulate deposits of Mylar or other tape coating oxides after the devices have been in use over an extended period of time. Small bits and pieces of the magnetic tape itself can also adhere to these components. Such accumulations on the playback head give rise to noise and distortion as the tape is played back. Further, the deposits on the drive capstan often result in slippage of the tape, causing wow and flutter as the tape is being played back, since the playback speed will not be constant.
In addition to the clear need for servicing these components by cleaning same, certain tests or checks should also be performed at regular intervals to ensure that the playback unit is functioning properly. For example, it is very important that the tape playback head be maintained in proper alignment, both with respect to azimuth (angle) and height, since a misaligned head can cause crosstalk between adjacent tracks on the tape. Proper operation of the sensing poles is also important, since they are utilized to automatically shift the playback head from one tape track to another when they are shorted by a small metal strip at the end of the tape.
In the past, servicing of the tape playback head, the drive capstan and the sensing poles, as well as the other related components of the playback unit, required the laborious disassembly of the entire unit in order to gain access to these various parts. Such a procedure was obviously unsatisfactory from an economic standpoint, since it required the services of a skilled maintanance person and was extremely time-consuming.
Certain solutions to the cleaning problem have been proposed. For example, one of the more common commercially available cleaning devices involves a cartridge having a cleaning tape coated with an abrasive material, substituted for the ordinary magnetic tape. This type of device has proven to be unsatisfactory in many respects among which are the undue wear which it causes on the playback head, the limited area of the drive capstan which it is able to clean, the wear on the drive capstan, and the build-up of foreign material which it causes on either side of the cleaning tape. Other cleaning devices of various sorts have also been proposed, but none of these has been entirely successful.
I am aware of the following patents, which are not necessarily prior art with respect to my invention, in this general area: U.S. Pat. Nos. 3,407,431, Melnick, 1968; 3,439,922, Howard, 1969; 3,594,850, Wellington, 1971; 3,647,990, Eul, 1972; 3,701,178, Kuntz, 1972; 3,761,994, Becht, 1973; 3,881,195, Ono, 1975; 3,955,214, Post, 1976; 3,997,919, Thompson, 1976.